


Sex Education

by kyowjin



Category: Shingeki no Kyojin | Attack on Titan, snk - Fandom
Genre: Awkward Sex, Blowjobs, M/M, eren embarrasses himself a lot, thats all that happens in this, they fuck and eren is hopeless
Language: English
Status: Completed
Published: 2013-07-18
Updated: 2013-07-18
Packaged: 2017-12-20 14:46:04
Rating: Mature
Warnings: Underage
Chapters: 1
Words: 3,023
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/888500
Author URL: https://archiveofourown.org/users/kyowjin/pseuds/kyowjin
Summary: <blockquote class="userstuff">
              <p>'But it made sense, really, for one whose mouth moves with such speed and dexterity - not to mention how <i>regularly</i> - would be good at giving head. Well, <i>above average</i> for a beginner anyway. Rivaille assumed with his tender age he had never even <i>seen</i> another man’s length before.'</p><p>Eren talks way too much and Levi really thinks he should teach him a lesson.</p>
            </blockquote>





	Sex Education

**Author's Note:**

> This actually is the first time I've written smut for SnK, ahh. Originally [from tumblr](http://kyowjin.tumblr.com/post/53669885119/sex-education) and it got some good comments so I guessed I'd post it here, too. Enjoy! ☆

Eren fucking  _babbled_. He spouted ridiculous and incoherent  _nonsense_  whenever it was inappropriate and never seemed to know when to stop. In fact, the only time he seemed to ever even hold his tongue was when it was occupied with something else - such as eating or maybe sucking cock, for example.

But it made sense, really, for one whose mouth moves with such speed and dexterity - not to mention how  _regularly_  - would be good at giving head. Well,  _above average_  for a beginner anyway. Rivaille assumed with his tender age he had never even seen another man’s length before.

Neither of them was entirely sure how they’d ended up in this situation. Honestly, everything was a little fuzzy for Rivaille and it seemed to take longer than usual for his thoughts to slowly come back to him. He found himself automatically thinking that although his senses  may be coming back, even though they were taking considerably longer than he liked at the moment, the one thing that definitely wasn’t going to be coming back (well, hopefully fucking not or there’d be hell to pay) was the cum that was making its way down into Eren’s digestive system right now. He gave into a smirk that he’d been fighting off for the last five minutes while the teen had been sucking him off.

The boy, who was still between his legs, looked horrified. His glassy green eyes were wide with shock (and most likely disgust as oh  _hell_  no; cumming in his mouth was  _not_  in any part of this odd predicament they’d gotten into) and his wet lips stood apart for a moment before curling into the most fearsome frown he could muster.

“ _What,_ " hissed the corporal with a smugly satisfied edge to his voice that made the hairs on Eren’s arms stand up.  
“What do you mean,  _‘what?’_!" Rivaille let his bored mask return to his face as he watched Eren rise from his most likely now bruised knees.

"I saved you the job of cleaning the mess. Be grateful. Also; is that any way to be speaking to your senior, brat?" He barked, lifting his leg and placing his boot on Eren’s tented crotch, who spluttered and stiffened in response. The younger felt his cheeks redden with embarrassment and arousal.

"Oi… Have you lost your voice or something? Honestly, all you did was moan a couple of times. Couldn’t have been that fucking stressful on your vocal chords, could it?" The shorter man applied more pressure to the taller’s crotch and watched his face tiredly.  
“Not like you to be at a loss for words, shit stain. You’ve usually always got something annoying to say."

It was actually true, thought Eren. He’d really run out of things to say. Well, there was always a, “sorry, sir" or maybe a “I’ll be going now, sir" but his stubbornness (and well, his  _stark arousal and general unwillingness to leave_ ) prevented him from saying such and making his escape.

He mulled a sentence over for the next 30 or so seconds but instead he found that his mouth just opened and closed like that of a goldfishes.

"Speak up."

More goldfish impressions. A long, deadly pause.

"Am I going to have to fuck the words out of you now, Jaeger? You’re the last person I’d expect to have to do that for."

The boot pushed further into his crotch and Eren relished in the slight, unexpected friction that radiated from it. Warmth spread like wildfire through his body and settled in the pooling heat in his stomach. His eyes slipped shut and he bit his lip coyly.

"What is it, boy? My words turning you on or something? Dirty fucker."

He couldn’t help it. He thrusted forward ever so slightly onto the sole of the boot that was now practically bullying his dick. The harsh  _tch_  that followed afterwards was almost proof that he shouldn’t have pushed the line.

"… If you’re that interested in my  _boot_  I’d love to see what you’d be like with the rest of me."

The tables turned far too quickly and easily onto himself for Eren’s liking but that was a blatant invitation, wasn’t it? That wasn’t like Corporal Rivaille at all. Maybe he just mocking him now? Damn, he made things so hard for him, the boy thought as the words began to spill from his mouth like a waterfall before he had a chance to realise he was even speaking.

"Oh, God, sir; I would fuck you senseless."

"How?" He shot back in less than a second and Eren  _flinched_.  
Eren opened an eye again just a touch to see Rivaille glaring at him (were they called bedroom eyes in this situation? - he didn’t know). His head was tipped back slightly displaying that deliciously pale neck of his and Eren couldn’t help but relate it to that of a submissive dog. But really - was he asking how he would manage to dominate him or how he would actually fuck him? He could feel words building up at the back of his sore throat and oh  _God_ –

"They say a picture paints a thousand words, sir."

"Oh then,” The sarcasm ripped through Eren like a knife through butter. “Would you like me to fetch your little colouring pencils and sketch book, kid?"

"N-no, sir! I’m just saying that if eyes are, uh,  _windows_  to the soul I don’t see why they can’t also be… Paint brushes." ‘Wow, smooth’, Eren mentally confirmed.

There it was. Rivaille smiled. Not a fake, sarcastic one. A real one, complete with the necessary glimmer in the eye. He even began to  _laugh_  and for a moment Eren began to laugh too - not really knowing what they were actually laughing about but hey, why not and plus –

"Oh,  _Jaeger_ , I think I was just sick in my mouth."

He pushed harder than was really necessary on Eren’s crotch and with an unsuspecting yelp, the younger of the two fell to his knees for the second time that night.

“S-sir!”

"Have to admit, that bullshit you just excreted there was pretty cute. You get points for trying; but no cigar unfortunately. Try again, brat."

Tears welled in Eren’s eyes as he glanced up at the man who he decided was Very Cruel Indeed and watched him as he rose from the stool he’d been occupying and strode towards him; looking down at him with his back still completely straight. Eren felt small.

"Cat got your tongue again, hm?"

"S-Sir, I would like to f-fuck you until your eyes roll and you bite through your own tongue! Until your entire body is b-bruised and bitten and  _loved_! I’d like to make you scream my name, Corporal Rivaille!" He ended his speech shouting and immediately regretted everything he’d ever said. Ever. He regretted the way he’d accidentally come onto the soldier while eating and agreed to suck his cock and oh for fucks sake he definitely regretted saying he’d like to ‘bruise and bite him’ and –

"Alright."  
"… Alright?"  
“Don’t make me repeat myself, fucker; I might just change my mind."  
“Sir, I’m not sure I follow this are you saying -"  
Another harsh, unnecessary nudge to the groin. “I’m telling you to fuck me, idiot. I said okay, didn’t I?"

Eren rolled onto his side on the floor and wheezed.

"Just one condition, brat. No cumming inside. If you do that I’ll rip out your neck right then and there with my teeth - titan or not."  
“A-alright."

The older man sat on the edge of the stool again and watched the boy below him struggle to his feet. He watched with a quizzical look as the other walked forward slowly and bent down, hooking his arm behind the back of his knees and the other around his back, his hand resting on his ribs.

Rivaille let himself be carried across to the bed that pushed against the east wall of the room and he did not complain as he was laid upon it like a child. He held his tongue as Eren climbed over him, sat on his thighs and began to unbutton his shirt.

"Don’t crease it." He whispered as his shirt was carefully removed and delicately folded and placed at the foot of the bed.

Their eyes met briefly as Eren leant down and began to kiss his hips while edging his trousers off. 

"Oi, brat. I’m bored."  
“Shut up, sir."

He began to kiss up his stomach and chest when the annoying cloth covering his long bruised legs was removed. Eren looked at the bruises for a while, opening his mouth and seemingly reverting back to a goldfish.

"3D manoeuvre gear. Unlike you, I don’t have a hyper healing ability. Neither does anyone else for that matter."

He frowned and twisted his torso so that he could get to Rivaille’s thighs, kissing along the bouquet of bruises that flourished on his hips. The corporal let his eyes slip shut and allowed his muscles to relax into the mattress. He would swear the brat to secrecy later.

"Hmm, how long do you plan on wasting time kissing me, huh? You can do that afterwards, stupid."  
“W-well it’s my first time sir and you’re just so… Handsome."  
“Don’t."  
“Sorry."

Eren ran his tongue over a nipple and felt the man’s muscles tighten in what he assumed was a positive way underneath him. His expression however did not change, and for a moment the brunet wondered if he’d actually fallen asleep.

He nibbled as gently as he could on the hardening ball of skin below him and breathed hotly on his chest, rubbing the other nipple with his free hand. The way the corporal’s breath hitched was all the encouragement he needed. He figured he was on the right tracks.

Sighing softly, the shorter of the two lifted his hands to the back of the taller’s neck, twirling and stroking the thick hair that grew there tenderly and encouragingly because, fuck, if he didn’t he figured he’d be bored out of his brains forever. The kid was taking too long for his own tastes but he guessed he should grant him more of a special first time than the quick fuck he wanted. After all, good things come to those who wait, right? Or was that bullshit too? Sounded like it. It was most likely bullshit.

After a few minutes Eren’s crotch finally found Rivaille’s and began to slowly rut against it like a child testing how much pressure it would take for a wooden spoon to snap - with extreme caution and uncertainty. Planting hot, wet kisses against his superiors neck and shoulders; edging down to suck on his collar bone - Eren was still somewhat lost for words.

He couldn’t quite remember how they’d ended up in a dreadfully sexual situation for the second time today.

Thankful for the friction, both men (boys?) let out soft sighs - not quite a moan or a whine, but as the speed and pressure -  _need_  - began to increase, so did the decibels the two were producing.

"Eren. Just fuck me already."

The sound of his first name being spoken like that sent a red hot wave through his torso and to his dick which twitched nervously in response. He swallowed thickly. “Alright."

Spreading Rivaille’s firm thighs and actually seeing the puckered hole for the first time scared Eren. He was in too deep. He couldn’t handle his corporal lying there so seemingly defenceless and pink around the edges. He was drowning.

"Anyone would assume from the gusto you had in your little speech earlier that you’d know what you were doing,” he sighed. “Clearly not. Fingers."  
It wasn’t a request, Eren deduced; it was an order, and orders were made to be followed.

Eren moved his forefinger and middle finger to the hot flesh that awaited him only to -  
“Start with one, you fucking imbecile."  
“You said finger _s_."  
"…"  
" _Sir._ ”

Eren shoved his forefinger in much rougher than he’d intended and he was dealt a disapproving ‘tch’ for his hasty actions. But he didn’t care.  
It was hot and slightly damp, he noted, curling his finger slightly to feel properly. Rivaille hissed. He stopped.

It seemed to be a matter of primal instinct after that. A sort of, find the hole and fuck it sort of instinct. And as he slid in his middle finger and began to scissor his corporal he remembered the infamous advice - ‘Always trust your instincts.’

It was disgusting the way the boy spat on his free hand and slathered his cock with it. Rivaille felt his insides churn and he lolled his head to the one side to distract himself from the abomination that was happening between his legs.

The next thing he knew was the rippling sensation of unexpected arousal spreading from his now cock occupied -  _cockupied_  - arse hole all the way up to his head before diffracting down his arms and then dissipating from his finger tips. The second thing he knew was that he had just released the most guttural and  _rich_  moan he had ever produced.

Eren obviously had deemed such a noise impossible and  _deliciously illegal_. He decided in that split second that he wanted  _more_  of it.

At first the thrusting was slow, uneven and embarrassingly shallow. Quiet groans of what was now discomfort emanated from Rivaille’s throat and Eren took it as his cue to get better.

He began to build up a rhythm that the corporal was quick to pick up on and follow by moving his hips to meet the others with almost perfect timing. As the pace set in it became much easier for him to aim deeper, Eren found, and with no time at all - later Rivaille would say it was because of his  _excellent guidance_  - he had gotten the hang of the ropes.

"You have h-hands, don’t you?" Breathed the man under him and Eren quickly found that there was more than just the set of ropes he’d gotten accustomed to. His general coordination he soon found was poor. His right and left hands could not operate independently of each other and he ran head on into difficulty as he tried to both tease Rivaille’s nipples and pump his cock. It was, in one word; disastrous. Eren had let go of all the ropes he thought he had mastered at once.

"N-nipples," huffed Rivaille as he thrust his hips down to meet Eren’s in an attempt to get him thrusting again. He swatted the tanned hand away from his cock and replaced it with his own and began to pump it in time with the thrusts. The whole thing was just a well choreographed dance, Eren noted as he began to tease one of the corporal’s nipples with one hand and hold his purple-green hips with the other. Until now he’d managed to keep eye contact but now his eyes drifted to Rivaille’s hand wielding his own dick and  _God_  was it turning him on.

The air in the room had grown hot and heavy as the two soldiers began to reach their breaking points. Sweat trickled down their backs as the thrusts had become more erratic and harder and faster and Rivaille wasn’t sure how much more he could take. Eren had lasted much longer than he thought he would (honestly he’d been expecting no more than 30 seconds, then he remembered that Eren wasn’t really your  _average_  horny teenage boy) and he was finding it hard to hold on. The air felt heavy in his lungs and his slick black hair stuck to his face with sweat. Eren was almost completely doubled up over the top of him now; kissing his now less pale more marred and bite mark encrusted neck as he desperately willed his stomach muscles to carry on his thrusting.

Rivaille gripped Eren’s back and dug in his spotless nails. His head tipped back and a thick moan - heck, it was nearly a  _cry_  - erupted from his throat as he released all over himself. The intense orgasm that took over overrode his disgust. It also overrode the fact that Mankind’s Greatest Soldier was now gripping a fifteen year old and the bed sheets for dear life so hard that his knuckles were white. Thankfully, though, it didn’t override the delightful mewling noises Eren was making and  _holy fucking shit that little fucker just came inside didn’t he_.

“Oh my God. Oh my God, Corporal I am _so sorry_.” Eren blurted out as soon as his senses came back to him and he realised his fatal mistake.  
“What did I say earlier, Jaeger?”  
Eren flinched again. He’d been demoted back down to second name basis.  
“N-not to c-cum inside, sir.”  
“Mh, hm. And what would I do if you did?”  
“Hah, now, sir; l-let’s be rational here!”

Moving quickly, the older man grabbed the back of Eren’s head with his right hand and pulled his head back, exposing the soft underside of his neck He moved his own head up to his throat where he opened his mouth and prepared to bite out his windpipe – maybe sever his jugular. He was undecided. He could smell Eren’s sudden fear and saw his eyes squeezed shut – bracing himself for the worst, obviously: but instead the corporal just planted a light kiss upon his Adam’s Apple.

“Don’t worry about it.” He said softly, letting go of the boy and lying back against the bed with an exasperated sigh. “Just get your dick out of me.”  
“Oh, right, right sure.”

They lay side by side for a while, both of them breathing somewhat faster than normal as they tried to reduce themselves to normality again. Rolling onto his side to face the older man – who was having significantly more trouble regaining his breath than himself – Eren lightly kissed his shoulder. He moved up to kiss his neck, chest and collar bone before moving to his cheek, forehead, chin, nose and finally his lips.

“What the hell are you doing now, brat? I’d quite like to sleep.”

“Well, you said I could kiss you afterwards, sir.”


End file.
